COLL 337 |
| Ying Zhang1, Valeria T. Milam2, David J. Graves1, and Daniel A. Hammer2. (1) Department of Chemical and Biomolecular Engineering, University of Pennsylvania, 311A, 220 S. 33rd Street, Philadelphia, PA 19104, (2) Department of Bioengineering, University of Pennsylvania, 120 Hayden Hall, 3320 Smith Walk, Philadelphia, PA 19104 |
| In this paper, we use DNA-functionalized micron-sized particles as alternative hybridization labels to nanoparticles or fluorescently-tagged target strands in a bead-based adhesion system for DNA detection. We allow microspheres coated with single stranded oligonucleotides to contact a surface functionalized with single stranded oligonucleotides under quiescent conditions, and then attempt to detach particles from the surface under an applied flow. The oligonucleotides on the microspheres hybridize specifically to regions on the substrate surface functionalized with the complementary sequence. We also studied the effects of applied shear force on adherent microspheres to find the critical shear stress necessary to break the hybridization bonds between the particles and substrate. The results show that micron-sized colloidal particles can be engineered to adhere specifically and that critical shear stress to detach beads increases with the number of base pair matches or with the ionic strength in hybridization buffers. In the future we will study the experimental sensitivity of the system to point mutations and investigate the relationship between bead adhesions to DNA chemistry. |
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Bio-Colloids
2:00 PM-4:40 PM, Tuesday, March 30, 2004 Marriott -- Orange County 3, Oral
Division of Colloid and Surface Chemistry |